Technical Field
The present invention relates to a method for additive manufacturing of a three dimensional article by successively fusing individual layers of powder material.
Related Art
Freeform fabrication or additive manufacturing is a method for forming three-dimensional articles through successive fusion of chosen parts of powder layers applied to a worktable.
An additive manufacturing apparatus may comprise a work table on which the three-dimensional article is to be formed, a powder dispenser or powder distributor, arranged to lay down a thin layer of powder on the work table for the formation of a powder bed, a high energy beam for delivering energy to the powder whereby fusion of the powder takes place, elements for control of the energy given off by the energy beam over the powder bed for the formation of a cross section of the three-dimensional article through fusion of parts of the powder bed, and a controlling computer, in which information is stored concerning consecutive cross sections of the three-dimensional article. A three-dimensional article is formed through consecutive fusions of consecutively formed cross sections of powder layers, successively laid down by the powder dispenser.
In additive manufacturing a short manufacturing time and high quality of the finalized product is of outmost importance. What is also important is to reduce servicing of the additive manufacturing apparatus as much as possible. The life time of the cathode element is one thing which constantly requires service in form of exchange when being worn out. It is desirable to extend the lifetime of the cathode element. Today the electron beam source settings is mainly performed manually which may introduce settings which reduces the lifetime from the very outset and/or after a period of time when the performance of the cathode element has changed.